The present invention relates to a fitting arrangement for an antivibration mounting of an electromotor on a load-bearing component by means of several interelements arranged distributed around the perimeter and consisting of an elastic material.
An example of such a motor mounting is described in the prior printed publication DE4306588A1. In this known motor mounting, elastic interelements (isolators) are radially situated with positive locking between the motor casing and an external motor bracket and within the space enclosing the motor casing. For this, the motor casing features radially protruding retaining segments on the one hand, and the isolators are placed upon them with corresponding slots. On the other hand, each isolator supports itself in the radial direction on two supporting surfaces on the motor bracket side, each surface running at an acute angle to the radial. Precisely adapted isolators are required because of the positively locking base. In addition, the remaining parts must also be specially adapted; i.e. retaining segments, isolators, and supporting surfaces must be synchronized to each other in order to achieve the desired vibration reducing support. The motor""s special, radially protruding retaining segments can be troublesome in other applications, so that the motor can""t be introduced for particular missions. There is only limited elasticity because of the special design and fitting arrangement of the isolators, wherein the motor contains them and the retaining segments engage the isolators. To this extent, the vibration isolation or damping achieved here is still worthy of improvement.
DE3500867C2 describes an electromotor, that is fastened by a holding strip that is connected to the motor with an angle support by two diametrically opposite, block-like elements of elastomeric material. The angle support is tightly attached to the motor""s cover. The elastomeric elements are connected to both the holding strip and also the angle support by vulcanizing or gluing. Such a motor fastening may only be used for relatively small motors, because the load-carrying connection exclusively consists of material locking (vulcanization or adhesion). In addition, this also leads to fairly expensive production.
DE3638393C2 describes another fitting arrangement for vibration reducing mounting of an electromotor. A motor is fastened to a casing wall or mounting wall by elastomeric isolators in this case too. To do this, the vibrators are held in an opening of the mounting wall with positive locking. Moreover, the isolators are arranged pressed together defined between the motor and a fastening plate. Specifically, we are dealing with four separate circular isolators, which are situated in the corners of an imaginary square and form a punctiform layout to the respective motor and mounting plate. In principle, this known absorbing arrangement therefore has the same absorbing characteristics and the same stiffness axially and radially.
Finally, DE4405577A1 describes a vibration reducing fitting arrangement with a single-pieced elastic isolator, which is basically designed as disc-shaped. This isolator is attached to the motor by several screwed connections passing through the isolator on the one hand, and to the bearer by joining elements arranged displaced around the perimeter on the other hand.
Proceeding from the state of the art, it is the objective of the present invention to create a fitting arrangement of the generic type, which will always achieve optimum vibration isolation independently of the motor""s fitting position.
This is achieved according to invention, in that the interelements are designed as oblong, radially aligned web elements and are arranged axially, clamped under elastic prestress, between a mounting surface on the motor side and a seating on the bearer side. At the same time, the web elements are arranged in such a way, and are designed in such a way regarding their shape and elastic characteristics, that the connection between the electromotor and the load-bearing component, viewed from the motor""s perimeter or direction of rotation, is less rigid, i.e. lighter, deformable with less force, than in all other directions in space.
Through the development according to invention, it is achieved that the support in the axial direction features greater stiffness than in the motor""s peripheral direction or direction of rotation. The attachment of the motor to the respective load-bearing component is relatively stiff for five of a total of six degrees of freedom in space (three translational and two rotational degrees of freedom). A distinctly less rigid support is achieved in regards to the last degree of freedom, i.e. the motor""s sense of rotation, because in this direction the web elements according to invention are elastically deformed exclusively perpendicular to their longitudinal extension, because any imaginary circle around the axis of rotation always cuts the radially arranged web elements perpendicularly. According to invention, the motor""s torque can indeed be adequately supported on the one hand, but the disturbing torque roughness (ripple torque, cogging torque, commutation activity) will effectively be isolated or dampened toward the load-bearing component to advantage.
The fitting arrangement according to invention is suitable above all for the one-sided xe2x80x9coverhungxe2x80x9d fastening of electromotors, such as external rotor motors for blower drives.
Frictional locking in the system will first of all provide an anti-rotation element of the electromotor against relative rotation vis-à-vis the load-bearing component. This indeed occurs primarily through static friction, whereby undesired damping effects (non-linear frictional losses, etc.) are avoided. In addition to this, however, extra anti-rotation elements and/or centering aids can also be present, especially through positive-locking elements.
Additional developmental features of the invention are contained in the dependent claims and in the following-description.